There are three positions where you would read and it corresponds to each of the three fingers that you put down on the radial artery:

寸脈 (literally "inch pulse"), the top pulse which is on the thumb side

關脈 (literally "gate pulse"), the middle pulse

尺脈 (literally "foot pulse"; "foot" as in the measurement, not the body part), the bottom pulse, also referred to in some texts as 根脈 (literally "root pulse") which is on the elbow side of the middle pulse

There are also three states to the three positions that are read by the amount pressure the reader applies to the pulse:

浮, the superficial or surface reading

中, the middle reading

沉, the sunken or deep reading

That will give you a total of nine readings per side. The left and right hand are wired up differently, so if both sides must be read, you'll have 18 points of data.

In most people, their radial artery is in their wrist, just below either thumb. But in rare cases, it can be somewhere else. There are known instances of the pulse being on the back of the hand, 翻關脈, the "Inverted Pulse".

In someone who is near death, the bottom pulse will disappear altogether, even in the deep reading. This is how we can tell that it's almost their time.

There was also special mention of ethics related to this. If you can't get a deep bottom pulse reading on a person, YOU DON'T EVER SAY IT OUT LOUD. For one, you could be misreading something. And it's plain bad form to be causing the patient and their families stress, spouting stuff like that.

師傅 related a story of one irresponsible doctor who said his wife had no deep bottom pulse(!). His wife was very much alive and well when he said that, but it caused them both 2 weeks of anguish before they finally realized that it was just physically not possible for her to be lacking a deep bottom pulse.

Stress hinders healing and worse yet, can cause other problems that may not have existed before.